Asian Carps A. General Information: There are seven known Asian Carps that have been introduced into the United States: Scientific name(s):
Bighead Carp (Hypophthalmichthys nobilis)(5)
Silver Carp- (Hypophthalmichthys molitrix)(5)
Black Carp- (Mylopharyngodon piceus
Grass Carp- (Ctenopharyngodon idella)
Common Carp- (Cyprinus carpio)
Goldfish Carp- (Carassius auratus)
Crucian Carp- (Carassius carrassius)(1)
Appearance- They have small scales and their eyes are low on their heads. Females are generally a bit larger than males. They have no teeth and instead have comb-like structures which filter their food (5). Size/Weight- The size and weight for Asian Carps vary depending on what kind of Carp it is and how old. Their size can range anywhere from 24-30 inches and as long as 39-40 inches, depending on the fish. Their weight varies as well, but they can be anywhere between 40 to 60 pounds(5). B. Detailed Description: Life Cycle/Reproduction Information- In order for reproduction to be successful, Carps require bodies of water that hold some kind of current for their eggs to float and develop properly. In April and May Carps migrate in small groups of 15 to 25 fish at dusk and dawn in temperatures between 18 and 20 degrees Celsius to lay their eggs. Females generally carry 299 to 5400 eggs (2). Out-competing other species- The reason that Asian carps have become so successful in areas of the United States is not only for the lack of predators of their species but because of their soaring reproductive rates and victorious ability to crowd out native fishes. They out-compete species not only through the ways listed above but also for their tendency to consume large amounts of food normally eaten by the native fish- which eventually erase them completely(4). Bighead and Silver carps compete largely with larval fishes, bigmouth buffalo, freshwater mollusks, or clams, and paddlefish(2). C. Habitat and Distribution: Preferred habitat- Asian Carps occur naturally in temperate waters of China. They prefer warm-water rivers and impoundments. Distribution- Bighead and Silver carps are found mainly in the Mississippi River drainage system and Common and Grass carps have spread to nearly ever state in the US. They have spread as far as the Illinois River and are extremely close to the Great Lakes(4).
D.Impacts: Ecological Impacts- Asian Carps invading rivers such as the Illinois and Mississippi pose a very big threat to native fish because of their habit of eating excess amounts of paddlefish, gizzard shad and bigmouth buffalo’s food supply(5). The biggest fear is that the carps will invade the Great Lakes which would pose a big risk to the Great Lakes ecosystem(3) Human Impacts- Asian Carps are a danger to boaters because they periodically jump out of the water when frightened, injuring anyone in their path. The Silver carps are known to injure boaters or fishers by jumping out of the water and into their boats. They occur only in fresh waters(4).
E. History: Pathways/History- They originated in Eurasia Different Carps were introduced in different ways- both legal and illegal. The Silver and the Bighead carps are said to be brought to the United States in various ways. Some being that they were brought from China in the 1970’s by catfish farmers to remove algae and other matter from their ponds, some being that they had escaped from aquatic facilities, and some being that flooding allowed them to swim over to the Mississippi River and up to the Illinois River. The common and grass carps were introduced through government agencies. And the Black carp, though some have escaped into the Mississippi River, have not become established and mainly remain only in aquatic facilities(1). F. Control Measures: In a method to keep Asian Carps from spreading to the Great Lakes, U.S. EPA, the State of Illinois, the U.S. Army Corps of Engineers, the International Joint Commission, and the Great Lakes Fishery Commission are planning to build an electric barrier to keep the fish away(4). The barrier stretches two rows of electrodes across the river, approximately 220 feet apart. The electrodes pulse currents into the water which causes fish to turn back instead of passing through to the other side.The electric current poses no threat to people and costs 2.2 million dollars to create(3). Work cited 1. "Asian Carp." www.umesc.usgs.gov. 2 Oct. 2007. 19 Nov. 2008
<http://www.umesc.usgs.gov/invasive_species/asian_carp.html>. 2. "Hypophthalmichthys molitrix (Valenciennes, 1844)." www.nis.gsmfc.org. 22 June
1998. 21 Nov. 2003 <http://nis.gsmfc.org/
nis_factsheet.php?toc_id=189>. 3. "Invasive Species." www.Epa.gov. 9 Sept. 2008. 9 Sept. 2008
<http://www.epa.gov/greatlakes/invasive/asiancarp/index.html >. 4. "Listen to your lakes: Invasive species." www.sheddaquarium.org. 17 Nov. 2008
<http://www.sheddaquarium.org/greatlakes/invasivespecies.html >. 5. Wisby, Gary. "New Lake Threat: Asian Carp." www.greatlakesdictionary.org. 6 May
2002. 6 May 2002 <http://www.greatlakesdirectory.org/zarticles/
56asiancarp.htm>.
Asian Carps
A. General Information:
There are seven known Asian Carps that have been introduced into the United States:
Scientific name(s):
Appearance- They have small scales and their eyes are low on their heads. Females are generally a bit larger than males. They have no teeth and instead have comb-like structures which filter their food (5).
Size/Weight- The size and weight for Asian Carps vary depending on what kind of Carp it is and how old. Their size can range anywhere from 24-30 inches and as long as 39-40 inches, depending on the fish. Their weight varies as well, but they can be anywhere between 40 to 60 pounds(5).
B. Detailed Description:
Life Cycle/Reproduction Information- In order for reproduction to be successful, Carps require bodies of water that hold some kind of current for their eggs to float and develop properly. In April and May Carps migrate in small groups of 15 to 25 fish at dusk and dawn in temperatures between 18 and 20 degrees Celsius to lay their eggs. Females generally carry 299 to 5400 eggs (2).
Out-competing other species- The reason that Asian carps have become so successful in areas of the United States is not only for the lack of predators of their species but because of their soaring reproductive rates and victorious ability to crowd out native fishes. They out-compete species not only through the ways listed above but also for their tendency to consume large amounts of food normally eaten by the native fish- which eventually erase them completely(4). Bighead and Silver carps compete largely with larval fishes, bigmouth buffalo, freshwater mollusks, or clams, and paddlefish(2).
C. Habitat and Distribution:
Preferred habitat- Asian Carps occur naturally in temperate waters of China. They prefer warm-water rivers and impoundments.
Distribution- Bighead and Silver carps are found mainly in the Mississippi River drainage system and Common and Grass carps have spread to nearly ever state in the US. They have spread as far as the Illinois River and are extremely close to the Great Lakes(4).
D. Impacts:
Ecological Impacts- Asian Carps invading rivers such as the Illinois and Mississippi pose a very big threat to native fish because of their habit of eating excess amounts of paddlefish, gizzard shad and bigmouth buffalo’s food supply(5). The biggest fear is that the carps will invade the Great Lakes which would pose a big risk to the Great Lakes ecosystem(3)
Human Impacts- Asian Carps are a danger to boaters because they periodically jump out of the water when frightened, injuring anyone in their path. The Silver carps are known to injure boaters or fishers by jumping out of the water and into their boats. They occur only in fresh waters(4).
E. History:
Pathways/History- They originated in Eurasia Different Carps were introduced in different ways- both legal and illegal. The Silver and the Bighead carps are said to be brought to the United States in various ways. Some being that they were brought from China in the 1970’s by catfish farmers to remove algae and other matter from their ponds, some being that they had escaped from aquatic facilities, and some being that flooding allowed them to swim over to the Mississippi River and up to the Illinois River. The common and grass carps were introduced through government agencies. And the Black carp, though some have escaped into the Mississippi River, have not become established and mainly remain only in aquatic facilities(1).
F. Control Measures:
In a method to keep Asian Carps from spreading to the Great Lakes, U.S. EPA, the State of Illinois, the U.S. Army Corps of Engineers, the International Joint Commission, and the Great Lakes Fishery Commission are planning to build an electric barrier to keep the fish away(4). The barrier stretches two rows of electrodes across the river, approximately 220 feet apart. The electrodes pulse currents into the water which causes fish to turn back instead of passing through to the other side.The electric current poses no threat to people and costs 2.2 million dollars to create(3).
Work cited
1. "Asian Carp." www.umesc.usgs.gov. 2 Oct. 2007. 19 Nov. 2008
<http://www.umesc.usgs.gov/invasive_species/asian_carp.html>.
2. "Hypophthalmichthys molitrix (Valenciennes, 1844)." www.nis.gsmfc.org. 22 June
1998. 21 Nov. 2003 <http://nis.gsmfc.org/
nis_factsheet.php?toc_id=189>.
3. "Invasive Species." www.Epa.gov. 9 Sept. 2008. 9 Sept. 2008
<http://www.epa.gov/greatlakes/invasive/asiancarp/index.html >.
4. "Listen to your lakes: Invasive species." www.sheddaquarium.org. 17 Nov. 2008
<http://www.sheddaquarium.org/greatlakes/invasivespecies.html >.
5. Wisby, Gary. "New Lake Threat: Asian Carp." www.greatlakesdictionary.org. 6 May
2002. 6 May 2002 <http://www.greatlakesdirectory.org/zarticles/
56asiancarp.htm>.